A Review on Bush Encroachment Effect on Cattle Rearing in Rangelands

Document Type: Review and Short Length Article

Authors

1 Department of Biology, College of Natural and Computational Sciences, Dire-Dawa University, Dire-Dawa,Ethiopia

2 Ethiopian Biodiversity Institute, Wildlife studies, Mekele center, Mekele, Ethiopia

Abstract

Bush encroachment is an increase in woody plant density typically resulting in impenetrable thickets, suppressing palatable grasses and herbs. Moreover, bush encroachment is a globally observed phenomenon. Besides, increasing the density of unpalatable shrubs and trees has reduced the carrying capacity and threatens the sustainability of grazing animal production, especially in arid and semi-arid grasslands and savannas around the world. Bush encroachment is a serious environmental and economic problem. In addition, biodiversity, wildlife habitat and nutrient cycling (rates, magnitude, seasonability and spatially patterns) are affected by these changes in vegetation. Although the increases in woody plant abundance have widely noted, such elements as rates, dynamics, spatial patterns and approximation have not been well documented. However, land use practices such as increased grazing pressure and decreased fire frequency have been associated with shifts from grass to woody plant domination. The pastoralists have been using the traditional grazing management in order to cope up with the relatively arid conditions of the environment, prevent from overgrazing and ensure the sustainability of resource base. 

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Abiyot B. and Getachew T. 2006. The prosopis Dilemma, Impacts on Dryland Biodiversity and some controlling methods. Journal of the Dryland, 1(2): 158-164.

Amaha, K. 2006. Characterization of Rangeland Resources and Dynamics of the Pastoral production systems in the Somali Region of Eastern Ethiopia. PhD Thesis, University of the Free State, South Africa.

Archer, S. 1995. Herbivore mediation of grass-woody plant interactions. Tropical grasslands 29:218-235.

Archer S. 2010. Rangeland conservation and shrub encroachment: new perspectives on an old problem. In: du Toit J T, Kock R, Deutsch J C. Wild Rangelands: Conserving Wildlife While Maintaining Livestock in Semi-arid Ecosystems. Chichester: John Wiley and Sons Ltd., 53–97.

Archer, S., Schimel, D. and Holland, E. 1995. Mechanism of shrub land expansion – land use, climate, or Co2 climatic change, 29, 91-99.

Archer, S, Boutton, T., Hibbard. K. 2001 Trees in grasslands: Biogeochemical Consequences of woody plant expansion. In: Global Biogeochemical Cycles  in the Climate System, pp. 47 (Schulze, E., Harrison, S., Heimann, M., Holland,  E., Lloyd, J., Prentice, I. and Schimel, D. eds.), Academic Press, San Diego, USA.

Asner, G. Elmore, A., Olander, L., Martin, R., and Harris, T. 2004. Grazing systems, Ecosystem responses, and global change. Annual Review environment and resource, 29: 261-299.

Ayana A. 2002. The effect of clearing bushes and shrubs on range condition in Borana, Ethiopia. Tropical Grasslands, 36: 69-76.

Ayana A. 2007. The Dynamics of Savanna Ecosystems and Management in Borana, Southern Ethiopia. PhD Thesis, Norwegian University of Life Science, Norway.

Ayana A., Adugna, T. and Atilaw B.. 2006. The effects of physical environment on the condition of rangelands in Borana. Tropical Grasslands, 40: 33-39.

Aweto, A. and Dikinya, O. 2003. The beneficial effects of two tree species on soil properties in a semi-arid savanna rangeland in Botswana. Land Contamination & Reclamation, 11(3): DOI 10.2462/09670513.618.

Carlier, L., Rotar. I, Vlahova. M and Vidican. R. 2009. Importance and Functions of Grassland s. Agrobotanici, 37(1): 25-30.

Dougill, A. Heathwaite, A. Thomas, D. 1998. Soil water movement and nutrient cycling in semi-arid rangeland: Vegetation Change and System Resilience. Hydrological Process, 12:443-459.

Dougill, A. and Cox, J. 2007. Land degradation in the Kalahari new analysis and alternative perspectives. Retrieved from (http://www.odi.org.uk/pdn /papers/38c.pdf) on 20/1/2011.

Dougill, A. and Trodd, N. 1999. Monitoring and modeling open savannas using multisource information: analyses of Kalahari studies. Global Ecology and Biogeography, 8: 211-221.

Dougill, A., Thomas, D. and Heathwaite, A. 1999. Environmental change in the Kalahari: Integrated Land degradation Studies for Nonequlibrium Dryland Environments. Annuals of the association of American geographers, 89(3): 420-442.

Dregne, E. 2002. Land Degradation in the Drylands: International Center for Arid and semi-arid Land Studies. Texas Tech University Lubbock, Texas, USA.

Friedel, M., Laycock, W., and Bastin , G. 2000. Assessing rangeland condition and trends. In Field and Laboratpry method for grassland and animal production research. (Eds. Mannetje, L. and Jones, R.) CAB International, UK, PP27-261.

Gemedo Dalle, Maass, B. and Isselstein, J. 2006. Encroachment of woody plants and its impact on pastoral livestock production in the Borana lowlands, southern Oromia, Ethiopia. African Journal of Ecology, 44: 237-246.

Han, J., Zhang, Y., Wang, C., Bai, W., Wang, Y., Han, G. and Li, L. 2008. Rangeland degradation and restoration management in China. The rangeland Journal, 30: 233-239.

Hibbard, K., Archer, S., Schimel, D. and Valentine, D. 2000. Biochemical changes accompanying woody plant encroachment in a subtropical savanna. Ecology, 82(7): 1999-2011.

Holdo, R., Holt, R. and Fryxell, J. 2009. Grazers, browsers, and fire influence the extent and spatial patterns of tree cover in the Serengeti. Ecological Applications, 19(1): 95-109.

Hudak, A. 1999. Rangeland Mismanagement in South Africa: Failure to Apply Ecological Knowledge. Human Ecology, 27: 55-78.

Hudak, A. and Wessman, C. 2001. Textural analysis of high resolution imagery to quantify bush encroachment in Madikwe Game Reserve, South Africa, 1955-1996.International Journal of Remote Sensing, 22(14): 2731-2740.

James, L., Young, J., Sanders, K. 2003. A New Approach to Monitoring Rangelands. Arid Land Research and Management, 17: 319-328.

Laliberte, A., Rango, A., Havstad, K., Paris, J., Beck, R., McNeely, R. and Gonzalez, A. 2004. Object-oriented image analysis for mapping shrub encroachment from 1937 to 2003 in southern New Mexico. Remote sensing of Environment, 93: 198-210.

Khavhagali, V. 2010. Poster Presentation: Importance, Threats, Status and Conservation challenges of Biodiversity in Northern Cape.

Lopez D., Cavallero M., Brizuela M. and Aguilar M. 2011. Ecosystemic structural–functional approach of the state and transition model. Applied Vegetation Science, 14: 6–16.

Meik, J., Jeo, R., Mendelson, J. and Jenks, K. 2002. Effects of bush encroachment on an assemblage of diurnal lizard species in central Namibia. Biological conservation, 106: 29-36.

Meyer, K. 2006. Cyclical succession in semi-arid savannas revealed with a spatial simulation model. PhD Thesis, Friedrich-Schiller-University, Germany.

Mugerwa, W. 2001. Rangelands Management Policy in Uganda. A paper prepared for the International Conference on Policy and Institutional Options for the Management of Rangelands in dry Areas, Hammamet, Tunisia.

Mugasi, S., Sabiiti, E. and Tayebwa, B. 2000. The economic implication of bush encroachment on livestock farming in rangelands of Uganda. African Journal of Range & Forage Sciences, 17(1, 2&3): 64-69.

Oba, G. and Kaitira, L. 2006. Herder knowledge of landscape assessments in arid rangelands in northern Tanzania. Journal of Arid Environments, 66: 168-186.

Oba, G. and Kotile, D.G. 2001. Assessments of Landscape Level Degradation in Southern Ethiopia: pastoralists Versus Ecologists. Land Degradation and Development, 12:461-475.

Riginos, C., Grace, J., Augustine, D. and Young, T. 2009. Local versus landscape –scale effects of savanna trees on grasses. Journal of Ecology, doi: 10.1111/j.1365-2745.01563.x.

Riginos, C. and Young, T. 2007. Positive and negative effects of grass, cattle, and wild herbivores on Acacia saplings in an East African Savanna. Oecologia, doi 10.1007/s00442.

Roques, K., O’Connor, T. and Watkinson, A. 2001.Dynamics of shrub encroachment in an African savanna: relative influences of fire, herbivory, rainfall and density dependence. Journal Applied ecology, 38:268-280.

Sala, O., Lauenroth, W., Mc Naughton, S., Rusch. G. and Zhang, X. 1996. Biodiversity and Ecosystem Functioning in Grasslands: Functional Roles of Biodiversity. In: A global perspective, Pp.131 (Mooney, H., Cushman, J., Medina, E., Sala, O. and Shulze, E. eds.).

Scholes, J. and Archer, S. 1997. Tree-grass Interactions in Savannas. Annual Review of Ecology and Systematics, 28:517-544.

Sheuyange, A., Oba, G., Weladji, R.,  2005. Effects of Anthropogenic Fire History on Savanna Vegetation in Northeastern Namibia. Journal of Environmental Management, 75: 189-198.

Schroter, M., Jakoby, O., Olbrich, R., Eichhorn, M. and Baurngartner, S. 2009. Remote Sensing of bush encroachment on commercial cattle farms in semi-arid rangelands in Namibia. Working Paper Series in economics, University of Luneberg, Germany.

Sweet, J. 1998. Livestock-coping with drought: Namibia- A case study. A paper prepared for the Grassland Group of the Crop and Grassland Service of FAO. Northern Regions Livestock Development Project, Tsumeb, Namibia.

Tesfaye D., Azage T., Lisanework N. and Worku T. 2010. Rangeland condition and feed resources in Metema District, North Gonder Zone, Amhara Region, Ethiopia. Working paper, Improving Productivity and Market Success of Ethiopian Farmers project (IPMS) - International Livestock Research Institute (ILRI), Addis Ababa, Ethiopia.

Tobler, M., Cochard, R. and Edwards. 2003. The impact of cattle ranching on large-scale vegetation patterns in a coastal savanna in Tanzania. Journal of Applied Ecology, 40: 430-444.

UNCED. 1992 Convention on Biological Diversity - A global biodiversity strategy. United Nations Conference on Environment and Development (Earth Summit, Rio de Janeiro, Brazil

Valone, T. and Thornhill, D. 2001. Mosquite establishment in arid grasslands: an experimental investigation of the role of kangaroo rats. Journal of Arid Environments, 48: 281-288.

Van Auken, O. 2000. Shrub invasions in North American Semi-arid Grasslands. Annual Review of Ecological System, 31: 197-215.

Walker, S. 1997. Models of vegetation dynamics in semi-arid vegetation: application to lowland central Otago, New Zealand. New Zealand Journal of Ecology, 21(2): 129-140.

Walker, B. and Janssen, M. 2002. Rangelands, pastoralists and governments:  interlinked systems of people and nature. The Royal Society, 720.

Ward, D. 2005. Do We Understand the Causes of Bush Encroachment in Africa Savannas? Africa Journal Range and Forage Science, 22: 101-105.

Wiegand, K., Ward, D. and Saltz, D. 2005. Multi-scale patterns and bush encroachment in an arid savanna with a shallow soil layer. Journal of Vegetation Science, 16: 311-320.

Wiegand, K., Saltz, D., Ward, D. 2006. A patch -dynamics approach to savanna dynamics and woody plant encroachment −Insights from an arid savanna. Evolution and Systematics, 7:229-242.

Wilcox, B. 2007. Does rangeland degradation have implications for global stream flow? Hydrological processes, DIO: 10.1002/hyp.6856.